For many years, water tables have been used to reduce air and noise pollution associated with various metal burning or cutting operations. Recently, there has been a renewed effort to produce and to use more efficient and less expensive means for controlling such pollution.
Prior water tables have included those which are an integral part of the plant floor. Some had sloped bottoms formed in floor material. One prior water table has a sloped bottom above the floor formed in a V-shape and a central sluice in the floor for receiving the burning wastes. Nozzles are positioned to jet water from headers over the sloped members to clean them and nozzles are also positioned in the sluice to jet water through the sluice to clean it. A similar water table includes means on each side of the V-shaped bottom member for providing a uniform flow of cooling water across the bottom and into a central sluice during the burning operation. Below the floor installations are undesirable for several reasons including the need for major excavation (usually of concrete) for the table and associated piping. This excavation and required maintenance can be very difficult and expensive.
Above-the-floor installations have been built. One of these comprised a tank, having sloped bottom members forming a V-shape, which was filled with water. It was located beneath a burning machine. No means was provided for circulating the water in the tank nor for cleaning the tank other than by emptying it.
Another above-the-floor water table has a single sloped bottom member for receiving burning wastes which pass into a waste recovery area where they are physically removed and dumped.
None of the water tables described, however, includes means for self-cleaning the table by selectively opening and closing a drain channel to permit flushing of the channel as desired.